Tipster Jane Manchun Wong tweeted Monday that the setting is available on the Android version of the social network's messenger in some countries, but only for a small group of users. Not every aspect of the app is converted, so it might switch back to the standard colors unexpectedly as you use it.

"Facebook Messenger, seemingly due to prolonged external nagging, has started public testing Dark Mode in certain countries," she wrote. "They have put up a fair warning that Dark Mode isn't everywhere yet so don't complain when some UI burns your eyes off."

She couldn't confirm which countries the test was happening in, but noted that the dark mode setting appears in the "Me" section of the app.